<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>

<style>

    * {
        margin: 0px;
        padding: 0px;
    }
    .box {
        width: 900px;
    }

    .top {
        height: 50px;
        background-color: pink;
        margin: 10px auto 0px;
    }
    
    .banner {
        height: 150px;
        background-color: purple;
        margin: 0px auto 0px;
    }

    .main {
        height: 500px;
        background-color: skyblue;
        margin: 0px auto;
    }

    .left {
        width: 500px;
        height: 500px;
        background-color: red;
        float: left;
    }

    .right {
        width: 300px;
        height: 500px;
        background-color: yellow;
        float: right;
    }

    .footer {
        height: 100px;
        background-color: black;
        margin: 0px auto 0px;
    }

</style>
</head>
<body>
    <div class="box top"></div>
    <div class="box banner"></div>
    <div class="box main">

        <div class="left"></div>
        <div class="right"></div>

    </div>
    <div class="box footer"></div>
</body>
</html>